"In the past decade, the number of internet users worldwide has grown exponentially. Today, almost 3 billion people are online, sending over 100 billion emails, Tweeting 500 million messages, and watching 3 billion YouTube videos every single day. Just as the internet has grown and changed, so has online marketing. Now there are many more departments, roles, and approaches. Here’s a cheat-sheet of online marketing roles to help you gain a better understanding of how you fit into the big picture."